Malicious PDF — malware analysis report

Static analysis result for SHA-256 e31de1e52d6d9b56…

MALICIOUS

PDF

80.5 KB Created: 2021-09-22 20:42:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: bc2da9f6b5870e55ddea1c52804c5601 SHA-1: 211f2a547980256e85abdd3ca71402402861037a SHA-256: e31de1e52d6d9b5639bf5f12091f8c62b244099f325005b5a950beef2bb26ad2
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains numerous external links, many pointing to compromised WordPress upload storage and disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware delivery. No scripts were extracted, but the structure and URLs point towards a social engineering attack.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9917

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • Small PDF is a non-clustered link farm on disposable hosting medium PDF_SEO_DISPOSABLE_LINK_FARM
    Small PDF contains many clickable external PDF links spread thin across many distinct hosts (no single dominant host), corroborated by a utm_term SEO-redirector link and/or links parked on free/disposable content hosts. This is the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains, rather than a normal document citation pattern. The PDF itself carries no exploit — the risk is the linked destinations.
  • External URI info PDF_URI
    PDF contains an external URL action
  • Object number defined twice with different bodies info PDF_DUPLICATE_OBJ_BODY_INCREMENTAL
    The same indirect object (N G) is defined more than once with different body bytes. First-wins and last-wins readers will resolve different content, which is a parser-confusion shape used by targeted PDFs. Body-only differences are common in benign incremental updates, so severity is raised only when the duplicate carries active content.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL https://penzion-pod-rozhlednou.cz/img/file/bipupexu.pdf In PDF document text
    • http://abpjseah.news-read.com/upload/files/44491692202.pdfIn PDF document text
    • http://mistral-paints.cz/userfiles/files/41363047031.pdfIn PDF document text
    • http://beastyenergy.com/userfiles/file/ladodevabopugokidekura.pdfIn PDF document text
    • http://transgusto.ch/userfiles/file/20111969568.pdfIn PDF document text
    • http://buzmakov-ua.ru/admin/ckfinder/userfiles/files/67455405236.pdfIn PDF document text
    • http://resumesfromabove.com/userfiles/file/mawupusadut.pdfIn PDF document text
    • http://kpdb.org/userfiles/files/24051312345.pdfIn PDF document text
    • http://xn--bqrr0jw6bmw2g.com/userfiles/file/1632254131.pdfIn PDF document text
    • https://thietbixanh.net/uploads/files/gerutoluwuwinowopofit.pdfIn PDF document text
    • https://bleikss.com/userfiles/file/negiwizawisuxiw.pdfIn PDF document text
    • https://srmhomes.com/images/bulk_images/files/46318356454.pdfIn PDF document text
    • https://cupanghitam.com/contents/files/82721174929.pdfIn PDF document text
    • http://dsfly.com/uploads/files/59117395285.pdfIn PDF document text
    • http://zoscm.zohukum.com/ckfinder/userfiles/files/mukagelaxetuj.pdfIn PDF document text
    • http://halvani.com/wp-content/plugins/formcraft/file-upload/server/content/files/16140be176f3dd---sikotiwige.pdfIn PDF document text
    • https://biocoop.legreniervert.fr/ckfinder/userfiles/files/sevevunere.pdfIn PDF document text
    • https://ymy-tea.tw/upload/files/gipoxaxodimafep.pdfIn PDF document text
    • http://travelcenterpuntos.com/campannas/file/37010608940.pdfIn PDF document text
    • http://akvatoria.by/UserFiles/files/rowepiz.pdfIn PDF document text
    • https://ofertaromania.ro/ckfinder/userfiles/files/34301939465.pdfIn PDF document text
    • https://staffxrecruitment.com/wp-content/plugins/super-forms/uploads/php/files/ced10bbedea9fa74ff3c65c97415347a/63774609928.pdfIn PDF document text
    • http://winso.tw/userfiles/file/89561630117.pdfIn PDF document text
    • https://asigurareingermania.ro/wp-content/plugins/super-forms/uploads/php/files/dg3gbr6vcrn2a9jjmeql8rki3f/68065922506.pdfIn PDF document text
    • https://nmcs.ca/userfiles/files/79005534330.pdfIn PDF document text
    • http://cokhivietuc.webthoidai.com/img-vietuc/files/zajigejivi.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/3vuEKuznOb8/uplcv?utm_term=how+to+download+any+app+in+sd+cardPDF link annotation
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d724.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD724 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ef36.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF36 16944 bytes
SHA-256: aef67e256ea893387d38682a4c312d56994f11e58d860dda39cc6155b495f6c5
font_02_sfnt_off00011bb1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11BB1 10568 bytes
SHA-256: 5fa11f00f9d29cde162ed0a4b3dd109622942e83f6acc31add0376b4476b26ec